Since a stative complement is not allowed to follow the undergoer NP after a transitive verb, a reduplication is generated to avoid a sequence of two complements. Hence, it appears that the undergoer NP and the stative complement each immediately follows a verb.
→ 他打球打得好 (t¯a d˘a qi´u d˘a de h˘ao/ He plays the (ball) game well.)
→ 他寫論文寫好了 (t¯a xiˇe l`unw´en xiˇe h˘ao le/ He had done the essay.)
Reference: Chinese: a linguistic introduction by Chao Fen Sun